In a traditional multiple-input multiple-output (MIMO) communications system, a transmit antenna of a base station (e.g., evolved Node B or eNodeB) includes multiple antenna ports in a horizontal direction, and includes one antenna port in a vertical direction. Different antenna ports are corresponding to different antenna elements. An antenna beam is synthesized by using different weighting vectors on different antenna ports or antenna elements (because of the different weighting vectors on the different antenna ports or antenna elements, a transmit or receive signal forms an antenna beam in a specific direction or region, that is, signal energy is relatively high or signal quality is relatively high in the specific direction or region). When a width of the antenna beam is relatively narrow, a coverage area of the antenna beam is limited. For example, an antenna beam of a fixed downtilt is formed in the vertical direction. When a width of the antenna beam is relatively narrow, a coverage area of the antenna beam of the fixed downtilt is limited, and system performance loss is relatively large. Therefore, how to effectively improve the coverage area of the antenna beam becomes an urgent problem to be resolved.